The German city of Hamburg likely avoided a major technological disaster on May 1, when a freighter ship caught fire. It had several tons of radioactive material and explosives among its cargo, it was revealed.

It took 200 firefighters working for several hours to douse the fires on the Atlantic Cartier. The ship’s most visible cargo was some 70 cars, 30 of which were damaged in the incident. But now it was revealed that the vessel also had highly dangerous substances on board as well, which posed the threat of radioactive contamination to the area.

Fire broke out the ship several hours after it arrived in the port of Hamburg. Three tugs and two fireboats were involved in fighting with the blaze, as firefighters unloaded shipping containers while cooling down the hull of the vessel with water. The ship was seriously damaged by the fire and remains in Hamburg.

The Atlantic Cartier was transporting around 9 tons of uranium hexafluoride, a radioactive highly violate and toxic compound most commonly used as an intermediate material in the production of nuclear fuel. The vessel also had 180 tons of flammable ethanol and 4 tons of explosives at the time the fire broke out.

The news of the averted disaster in Hamburg was broken by the opposition Green Party. It criticized the city authorities for not reporting the full details of the incident on its own initiative.

“It is an outrage that the Senate has not informed the public about this near catastrophe,” Greens’ member of the Hamburg parliament Anjes Tjarks said. “Here one must speak of a cover-up.”

The city responded by saying that the firefighters were informed of the dangerous nature of the cargo promptly, which is the reason why the containers in question were quickly removed from the ship.

“Thanks to the quick intervention, the harbor and the people in the area suffered from no hazard,” said city spokesman Frank Reschreiter. “There was no leak of the dangerous material.”

Hamburg regularly receives shipments of radioactive material, German media report. It is a convenient transit point to deliver them to the uranium-enriching facility in Lingen, Lower Saxony.